1. Field of the Invention
This invention relates to an electrically conductive joint, and more specifically to a joint formed of a strip of electrically conductive material having one surface coated with an electrically insulating coating, and which joint is useful in the fabrication of magnetic shielding for electrical apparatus.
2. Related Prior Art
It is known in the prior art to provide hollow housings for magnetic shielding of electrical apparatus. For example, U.S. Pat. No. 5,028,740 discloses such a housing comprising an electrically conductive sheet, one surface of which is coated the an insulating material such as a paint, resin, etc. A joint is formed by bending one end of a sheet of such material into a hairpin shape and connecting that bent end to the other end of the sheet by means of rivets or screws.
U.S. Pat. No. 2,876,275 shows a shielding panel comprising a rigid member, such as plywood, provided with a metal sheathing terminating in L-shaped portions which can be locked together to provide continuity of electrical conductivity from panel-to-panel.
U.S. Pat. No. 3,340,587 discloses electromagnetic shielding enclosures wherein panels are disposed in edge-to-edge relationship, with U-shaped spring clips into which panel flanges are inserted to provide an electrically continuous wall of panels.
U.S. Pat. No. 5,198,290 discloses an electromagnetic shielding material comprising a flexible base fabric, a first metallic film formed by flame-spraying a metal, such as Zn, on one side of the fabric, and a second metallic film, such as Al foil, formed on the other side of the fabric. No joint is shown.
U.S. Pat. No. 4,652,695 discloses a clip enclosing an end of a knit mesh material and adapted to be installed around the periphery of a door in a shielding enclosure to maintain electrical continuity in the enclosure.
None of such prior art provides a joint in a conductive metal sheet having one insulated surface, formed only by bending the sheet.